There have conventionally been known as stabilizers or fog restrainers to be used for the purpose of preventing silver halide photographic light-sensitive materials (hereinafter called light-sensitive materials) from producing a fog with the lapse of time a large number of compounds including, for example, hydroxypolyazaindenes such as 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene, mercapto-substituted heterocyclic compounds such as 1-phenyl-5-mercaptotetrazole, 2-mercaptobenzothiazole, and azole derivatives such as benzimidazole, benzotriazole, indazole, and the like.
Further, the combined use in a given ratio of these conventionally known fog restrainers is also extensively performed in this field.
However, the demand for increasing the speed of light-sensitive materials has been more and more strongly made in recent years. That is, there are, for example, light-sensitive materials for amateure use required to meet the need for the use of a high shutter speed for preventing the camera blur in photographing due to the miniaturization of the image frame size; color and black-and-white photographic papers required to meet the need for the rapid processing in the development process thereof; light-sensitive materials for graphic arts use required to be so high-sensitive as suitably usable in the electronically operated, simplified or automated plate-making and printing processes; light-senisitive materials for medical radiography use highly demanded to meet the need for use in a much reduced radiation-exposure dose to be highly safe to the human body; and the like.
Upon the fog to be produced during the storage over a long period of time in a light-sensitive material comprising a silver halide emulsion extremely sensitized or sensitized by a technique different from conventional ones or to be increased due to the rapid development process at a high temperature above 30.degree. C. that is performed lately for the reduction of the access time, those conventional fog restrainers as mentioned above has no effect at all or on the contrary there are cases where they rather increase the fog.
Thus, there is a strong demand for developing a fog-restraining technique which is capable of adequately restraining high-speed light-sensitive materials from producing a fog during their storage over a long period or of preventing light-sensitive materials from producing a fog in their rapid processing at a high temperature, and which has no influence upon the photographic characteristics (gradation, sharpness, etc.).